Process of treating glyceride oils



Patented Sept. 12, 1944 PROCESS or TREATING GLYCERIDE OILS Bernard A. Dnmbrow, New York, N. Y., assignor to National Oil Products Company, Harrison, N. J., a corporation of New Jersey No Drawing.

Application May 13, 1941,

Serial No. 393,187

9 Claims. (Cl. 260-4285) The present invention relates in general to the fractionation of fatty materials and in particular to an improved processof solvent. fractionation of glyceride-containing oils and fats.

It is well known that animal, vegetable and marine oils and fats are composed predominantly of triglycerides of the higher fatty acids having varying degrees of unsaturation. While the natural occurring oils and fats containing triglycerides of varying degrees of unsaturation have utility, the constituents thereof are far more valuable in their isolated form. For example, in the paint and varnish industries the unsaturated triglycerides find considerable use. Likewise many uses are found for the more saturated triglyc'erides.

The general object of this invention is to provide a simple and improved process of separating unsaturated triglycerides from a mixture of saturated and unsaturated triglycerides.

A specific object of the invention is to provide an improved process of producing drying oils from marine oils.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

In accordance with the'invention a mixture of saturated and unsaturated triglycerides of the higher fatty acids, such as are found in animal, vegetable and marine oils, is contacted with a hydroxy organic solvent in the presence or not of heat. The solvent oil mass is then allowed to separate into two layers, one layer containing a predominating portion oi the unsaturated triglycerides and solvent and the other layer containing th major portion of the saturated triglycerides present in the oil originally.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others thereof, which will be exemplified in the process here nafter disclosed, and the scope of the in-= vention will be indicated in the claims.

In carrying out the process of the invention any suitable composition containing a mixture of saturated and unsaturated glycerides of the glycerides may be either partially or completely esterified, i. e., they may be composed of either mono, di or triglycerides or a mixture thereof. However, inasmuch as the natural occurring oils contain substantially no mono or diglycerides, the treatment of triglyceride mixtures and particularly natural oils and fats is preferred. In accordance with the process of the invention naturally occurring oils, such as animal, vegehigher fatty acds may be employed. These I table and marine oils, including, inter alia, soya bean oil, linseed oil, cottonseed oil, cod oil, sardine oiL-tuna. oil, cod liver oil, tuna liver oil, shark oil, etc., maybe fractionated. The foregoing class of oils are composed essentially .of triglycerides of oleio, linoleio, linolenic, clupanodonio, licanic, elaeosteric, palmltic, stearic and like fatty acids.

According-to the process an oil of the foregoing type 'is contacted with a hydroxy solvent of the type which is characterized by being a better solvent for the unsaturated triglycerides than the saturated triglycerides. The preferred class of solvents includes, among others, alcohols having 1 .to 3 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol and chlorhydrin. The solvent or mixture of solvents is brought into contact with the oil in such a manner as to dissolve all the oil or only a portion thereof. The temperature of contact may be varied to suit the conditions at hand. In some cases it is desirable to heat the oil and solvent to dissolve all the oil in the solvent. Whether complete dissolution is effected or not, the oil-solvent mass is allowed to stand, whereby two layers are formed. In certain cases, especially where all or a major portion of the oil is dissolved in the solvent, chilling aids and/or accelerates the formation of two layers. The foregoing class of hydroxy solvents is characterized by selectively dissolving out the unsaturated triglycerides from a mixture thereof with saturated triglycerides. These solvents also possess the property of preferentially retaining unsaturated triglycerides in solution when the temperature of a solution of both saturated and unsaturated triglycerides is decreased. It may be seen, then, that the degree of dissolution in the solvent of the oil treated may be varied. In any event the temperature of dissolution of the oil and the subsequent layer separation step is controlled to give a solvent solution of a fraction rich in unsaturates. The solvent-oil ratio may be varied from 1 to 12 parts of solvent to one part oi oil.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following examples which aregiven merely to further illustrate the invention and are not to be construed'in a limiting sense.

Example I 92 grams of cod liver oil dissolved in cc. n-propanol and solution chilled to 17 0., whereby two layers were formed and subsequently separated. Th original oil had an iodine value of 150 and the solvent extracted oil gave an iodine value of 166.2.

Example II 94 grams of cod oil admixed with 150 cc. ethanol Example I II 450 cc. of sardine oil were admixed with 450 cc. of 95% isopropanol and heated to 62 C. after which the mass was cooled to below 29 C., whereupon two layers formed. .The layers were separated and the isopropanol layer was found to contain an oilfraction rich in unsaturates.

The fractions rich in unsaturates as produced in accordance with theprocess of this invention have been found to be admirably suited for use as drying oils. The degree of step up in iodine value of the solvent fraction over and above that of the original oil is dependent on the particular oil treated as well as the'solvent and conditions employed. The solvent may be removed from the unsaturated triglyceride fraction by any suitable method such as distillation.

Since certain changes may be made in carrying out the above process without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A process of selectively separating a fraction which is rich in unsaturated glycerides from a material containing said glycerides in admixture with a more completely saturated glyceride, wh'ch process comprises contacting the material with an organic solvent, said solvent beinga monchydroxy unsubstituted alcohol of from l3 carbon atoms, which at a low: temperature is relatively immiscible with the saturated glyceride, the temperature of treatment being above about minus 20 C., the ratio of solvent and the temperature being below that of complete miscibility with the glycerides, separating the two phases while they are both in liquid state, one containing primarily undissolved glycerides relatively poor in unsaturated glycerides and containing some solvent and the other consisting of solvent in which are dissolved glycerides relatively rich in unsaturates.

2. A process of treating a fatty oil to obtain therefrom a fraction rich in unsaturated triglyc erides, which comprises contacting the oil with a monchydroxy unsubstituted alcohol containing 1 to 3 carbon atoms, cooling the mass to induce the formation of two layers and separating the layers.

3. A process of treating a jflsh oil to'recover therefrom a fraction rich in unsaturated triglycerides, which comprises contacting a fish oil with a monchydroxy unsubstituted alcohol of from 1-3 therefrom a fraction rich in unsaturated triglycerides,v which comprises admixing a fish oil with a monohydroxy unsubstituted alcohol or from 1-3 carbon atoms, heating the mixture to dissolve at least a portion of the oil, cooling the mass to form two layers and separating the layers.

5. A process of treating a fatty oil to obtain therefrom a fraction rich in unsaturated triglyc erides, which comprises contacting the oil with isopropanol, cooling the mass to induce the formation of two layers and separating the layers. 6. A process of treating a fish oil to recover therefrom a fraction rich in unsaturated triglycerides, which comprises contacting the fish oil.

8. A process of treating a fatty oil to obtain therefrom a fraction rich in unsaturated triglycerides, which comprisescontacting the oil with ethanol, cooling the mass to induce the formation or two layers and separating the layers.

9. A process of treating a fatty oil to obtain therefrom a fraction rich in unsaturated triglycerides, which comprises contacting the oil with propane], cooling the mass to induce the formation of two layers and separating the layers.

BERNARD DOMBROW. 

